This invention relates to apparatus for assembling, shaping, machining, grinding and the like, more particularly to an improved support for positioning and holding a pallet that supports a workpiece to be operated on.
In the prior art, a great many types of clamping devices and support structures are known to hold workpieces during various shaping and machining operations known in the art.
With the advent of automated shaping operations it was inconvenient, and in general inefficient, to clamp a workpiece in a vise or other support which requires an individual accurate repositioning when the workpiece is moved to different machines for subsequent operations. This difficulty was alleviated by mounting the workpiece on a pallet, or providing a base on the workpiece which could be later removed. The pallet therefore provided a standardized reference element that could be repeatedly placed on suitable supports and removed as the situation required. In use the pallet and mounted workpiece can be moved to different standardized supports on different assembly, machining and shaping operations. A set of pallets can be used to hold a number of workpieces during a single or multi-operation on an automated apparatus, the apparatus changed to perform a different operation, and the set of pallets again processed through the subsequent operation.
In order that the pallets be effective, the support for the pallets must be capable of quickly and precisely locating the pallet relative to the machine in the X, Y and Z directions and thereafter firmly hold the pallet in the initial same precise aligned position. The pallet changing operation should be achieved with a very minimum of effort and in a very short time.
Pallet clamps for holding pallets are known. However, the pallet clamps known to the art have various limitations that limit their effectiveness. The known clamps may require a time consuming initial positioning, the pallet may not be sufficiently rigid to prevent movement during the machining operation, or even loosening, or the mechanism is prone to malfunctioning by debris encountered in the various operations.
What is needed in the art is an uncomplicated and reliable clamp that will repeatedly align a workpiece on a pallet to a machine, where the pallet changing operation is quick, simple and positive.